Heat-insulating lining for a footwear article and a footwear article including the same

ABSTRACT

A heat-insulating lining for a footwear article includes an enclosure body made from an air-impermeable thermoplastic material and defining an inner space, and a porous layer disposed in the inner space such that the enclosure body encloses the porous layer intimately. The inner space in the enclosure body is in a vacuum state.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese application no.200410098885X, filed on Dec. 20, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a heat-insulating lining for a footweararticle, more particularly to a heat-insulating lining including anenclosure body defining an inner space in a vacuum state, and a porouslayer intimately enclosed in the inner space of the enclosure body. Thisinvention also relates to a footwear article including theheat-insulating lining.

2. Description of the Related Art

Heat-insulating fabrics, such as heat-insulating resin fabrics and glassfibers, are commonly used in footwear articles, such as an outsole, alining, and an upper. While heat-insulating fabrics are useful for heataccumulation and insulation, they are unsuited for avoiding heat lossdue to heat conduction, heat convection, and heat radiation when used ina cold environment. While heat loss can be reduced by increasing thefabric thickness, the increased fabric thickness will result in acorresponding increase in the size and weight of the footwear article.Physical motions of the wearer will be impeded accordingly.

Another conventional method for reducing heat loss of a footwear articleis to stitch an aluminum foil layer and a heat-insulating resin fabrictogether, so as to diminish the heat radiation through the reflectiveproperty of the aluminum foil layer. However, since heat conduction andheat convection cannot be reduced through application of the aluminumfoil layer, the footwear article made from this conventional method hasa poor heat-insulating effect.

One conventional footwear article includes an upper having an upperenclosure that is lined with an inner lining sleeve by stitching. Theinner lining sleeve is made from waterproof and breathable fabrics. Theinner lining sleeve is capable of preventing intrusion of water into theinterior of the footwear article. However, when the footwear article isused in a severely cold climate, pores of the inner lining sleeve willcontract, and the moisture in the interior of the footwear articlecannot be effectively expelled out to the exterior of the footweararticle. Accordingly, the great temperature differential between theinterior and the exterior of the footwear article results incondensation of the moisture in the interior of the footwear article. Ascold air can permeate into the interior of the footwear article, watercondensate in the interior of the footwear article can freeze. As aconsequence, the footwear article loses its heat-insulating ability.

Another conventional footwear article includes an inner lining producedby the following steps: attaching respectively a fabric layer orheat-insulating resin layer to upper and lower surfaces of a plasticpiece made from EVA or PU material, so as to form a pre-product; andcutting and stitching the pre-product so as to form an inner lininghaving a shoe shape. The inner lining thus made can be disposed infootwear articles, such as a shoe or a boot, to intimately enclose thefoot of the wearer. However, although the inner lining can stop the coldair outside from permeating therethrough, gradual heat loss andcondensate freezing attributed to heat conduction, heat convection, andheat radiation cannot be avoided.

Therefore, there is a need for a footwear article that is suitable foruse in severely cold climates and that can minimize wearer discomfortattributed to heat conduction, heat convection and heat radiation.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide aheat-insulating lining for a footwear article, and footwear articlesincluding the heat-insulating lining that are clear of the aforesaiddrawbacks of the prior art.

According to one aspect of this invention, includes an enclosure bodymade from an air-impermeable thermoplastic material and defining aninner space, and a porous layer disposed in the inner space such thatthe enclosure body encloses the porous layer intimately. The inner spacein the enclosure body is in a vacuum state.

According to another aspect of this invention, a footwear articleincludes an outsole, an upper interconnected with the outsole so as todefine a wearing space therebetween, and the heat-insulating lining asdescribed above disposed in the wearing space and attached to theoutsole.

According to still another aspect of this invention, a footwear articleincludes an outsole, an upper interconnected with the outsole so as todefine a wearing space therebetween, the upper including a skin layerand an inner lining confronting the skin layer, and the heat-insulatinglining as described above that is sandwiched between the skin layer andthe inner lining of the upper and that is attached to the outsole.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments of this invention, with reference to the accompanyingdrawings, in which:

FIGS. 1 and 2 respectively are inverted exploded perspective andschematic views to illustrate the first preferred embodiment of aheat-insulating lining for a footwear article according to thisinvention;

FIG. 3 is a schematic sectional view to illustrate the second preferredembodiment of a heat-insulating lining for a footwear article accordingto this invention;

FIG. 4 is a schematic sectional view to illustrate a structuralmodification of the second preferred embodiment shown in FIG. 3;

FIG. 5 is a schematic sectional view to illustrate the third preferredembodiment of a heat-insulating lining for a footwear article accordingto this invention;

FIGS. 6 and 7 respectively are perspective and fragmentary sectionalviews to illustrate the fourth preferred embodiment of a heat-insulatinglining for a footwear article according to this invention;

FIG. 8 is a schematic sectional view to illustrate the first preferredembodiment of a footwear article according to this invention, whichincludes an outsole having the heat-insulating lining of FIG. 2 attachedthereto; and

FIGS. 9 to 12 are fragmentary schematic sectional views to illustratethe second preferred embodiment of a footwear article according to thisinvention, which includes an upper integrated with the heat-insulatinglining of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, the first preferred embodiment of aheat-insulating lining 100 for a footwear article according to thisinvention includes a porous layer 1 and an enclosure body 3. Theenclosure body 3 is made from an air-impermeable thermoplastic material,and has an inner layer 31 and an outer layer 32. The inner and outerlayers 31, 32 define an inner space 33. The porous layer 1 is disposedin the inner space 3 such that the enclosure body 3 encloses the porouslayer 1 intimately.

Preferably, the air-impermeable thermoplastic material for preparing theenclosure body 3 is selected from the group consisting of nylon,polyethylene (PE), thermoplastic polyurethane (TPU), polyethyleneterephthalate (PET), polyvinyl alcohol (PVA), polyacrylonitrile (PAN),and combinations thereof.

The porous layer 1 is made from a porous elastic material. Preferably,the porous elastic material is selected from the group consisting ofopen-cell type polyurethane, polyesterresin, glass fiber, open-cell typepolyethylene, open-cell type ethylene-vinyl acetate copolymer, andcombinations thereof. More preferably, the porous elastic material isopen-cell type polyurethane.

Preferably, the porous layer 1 further contains molecular sieve formoisture absorption, and active carbon for deodorization. In thepreferred arrangement, the porous layer 1 has a top surface 13 and abottom surface 14 opposite to the top surface 13. The bottom surface 14has a honeycomb structure. The porous layer 1 is formed with a pluralityof cavities 11 with a hexagonal section dented from the bottom surface14, and a plurality of air channels 12, which have been magnified inFIG. 2 for ease of understanding, that pass through the porous layer 1from the bottom surface 14 to the top surface 13 and that are in fluidcommunication with the cavities 11. The presence of the cavities 11 canreduce weight without sacrificing structural strength. The presence ofthe air channels 12 can stop heat conduction in the interior of theporous layer 1 attributed to air trapped therein. In addition, theporous elastic material used for manufacturing the porous layer 1 ispreferred to have a black color so as to lower the heat-conductivitycoefficient and to reduce heat loss attributed to heat radiation.

Preferably, the heat-insulating lining 100 further includes tworeflecting layers 2 that are interposed between the outer layer 32 ofthe enclosure body 3 and the porous layer 1 and between the inner layer31 of the enclosure body 3 and the porous layer 1, respectively. Each ofthe reflecting layers 2 is made from a metal material having lowheat-conductivity so as to minimize heat radiation. Preferably, themetal material is aluminum foil.

During the manufacture of the heat-insulating lining 100 of thisinvention, the inner and outer layers 31, 32 of the enclosure body 3 areconnected peripherally to each other, and an opening 34 in communicationwith the inner space 33 is formed therebetween. The porous layer 1 andthe reflecting layers 2 are inserted into the inner space 33 through theopening 34. Thereafter, the inner space 33 is vacuumed using a vacuumpump (not shown) through the opening 34, and the opening 34 issubsequently sealed through a high-frequency welding technique or by avacuum packaging machine, so as to keep the inner space 33 in theenclosure body 3 in a vacuum state. The enclosure body 3 is thus formedinto an air-impermeable vacuum body.

FIG. 3 shows the second preferred embodiment of the heat-insulatinglining 100 for a footwear article according to this invention. Thesecond preferred embodiment is similar to the first preferred embodimentof this invention illustrated in FIGS. 1 and 2, except that a foam layer5 and a fabric layer 4 are further included. In this embodiment, theenclosure body 3 has an outer surface with upper and lower sides formedfrom the inner and outer layers 31, 32, respectively. The foam layer 5is attached to one of the upper and lower sides of the outer surface ofthe enclosure body 3. The fabric layer 4 is attached to the outersurface of the enclosure body 3 through the foam layer 5. Theheat-insulating lining 100 of this embodiment is suitable forapplication to an insole.

FIG. 4 illustrates a structural modification of the second preferredembodiment of FIG. 3. In this embodiment, the foam layer 5 is attachedto one of the upper and lower sides of the outer surface of theenclosure body 3. The fabric layer 4 is attached to the other of theupper and lower sides of the outer surface of the enclosure body 3, sothat the enclosure body 3 is interposed between the fabric layer 4 andthe foam layer 5.

The foam layer 5 used in the second embodiment shown in FIGS. 3 and 4 ismade from an elastic and cushioning material, such as EVA, PU, or TPU.

When the heat-insulating lining 100 shown in either FIG. 3 or FIG. 4 isdisposed in a footwear article, the inner space 33, which is in a vacuumstate, does not promote air circulation. Hence, heat conduction and heatconvection can be efficiently inhibited. In addition, the reflectinglayers 2 that are interposed between the outer layer 32 of the enclosurebody 3 and the porous layer 1 and between the inner layer 31 of theenclosure body 3 and the porous layer 1 can efficiently impede heatradiation. In addition, in view of the porous layer 1 being made fromthe porous elastic material, the contact area between the porous layer 1and the reflecting layers 2 is decreased so as to further enhanceinhibition of heat conduction and heat conduction. Therefore, the heatloss from the interior to the exterior of the footwear article can beminimize effectively.

As shown in FIG. 5, the third preferred embodiment of a heat-insulatinglining for a footwear article according to this invention is similar tothe embodiment illustrated in FIG. 4, except that a heat-insulatinglayer 50 is further included between the fabric layer 4 and the other ofthe upper and lower sides of the outer surface of the enclosure body 3,so that the fabric layer 4 is attached to the enclosure body 3 throughthe heat-insulating layer 50. The heat-insulating layer 50 is made froma foamed resin, such as heat-insulating resin, so as to enhance theheat-insulating effect of the heat-insulating lining.

FIGS. 6 and 7 illustrate the fourth preferred embodiment of aheat-insulating lining 6 for a footwear article according to thisinvention. The fourth preferred embodiment of this invention is similarto the first preferred embodiment of this invention illustrated in FIGS.1 and 2, except that two foam layers 5 are attached to the upper andlower sides of the outer surface of the enclosure body 3, respectively.

In this embodiment, the heat-insulating lining 6 is formed into a shoeshape and is adapted to be inserted into a shoe. Particularly, theheat-insulating lining 6 includes a left upper portion 61, a right upperportion 62 and an outsole portion 63 connected to the left and rightupper portions 61, 62 through a stitching or gluing technique.

Referring to FIG. 8, the first preferred embodiment of a footweararticle according to this invention is illustrated. The footwear articleof this embodiment includes an outsole 7, an upper 70 interconnectedwith the outsole 7, so as to define a wearing space therebetween, andthe heat-insulating lining 100 shown in FIG. 2 that is disposed in thewearing space and that is attached to the outsole 7. Preferably, theoutsole 7 is formed with a cavity 72 so as to receive fittingly theheat-insulating lining 100.

Referring to FIGS. 9 to 10, the second preferred embodiment of afootwear article according to this invention includes an upper 8 and anoutsole 83. The upper 8 is interconnected with the outsole 83 so as todefine a wearing space therebetween. The upper 8 includes a skin layer81, an inner lining 82 confronting the skin layer 81, and a lining space84 defined therebetween. The heat-insulating lining 100 shown in FIG. 2is intimately sandwiched between the skin layer 81 and the inner lining82 of the upper 8 in the lining space 84, and is attached to the outsole83. Preferably, the heat-insulating lining 100 is peripherally stitchedtogether with the skin layer 81 and the inner lining 82 of the upper 8or is glued together with the skin layer 81 and the inner lining 82 ofthe upper 8. FIG. 10 is an enlarged view of a part of the upper 8 of thefootwear article shown in FIG. 9.

Preferably, as shown in FIG. 11, the outsole 83 includes theheat-insulating lining 100 shown in FIG. 4, so as to enhance theheat-insulating effect of the footwear article. Alternatively, as shownin FIG. 12, the heat-insulating lining 100 extends with the inner lining82 to enclosure the entire wearing space.

According to this invention, since the enclosure body 3 of theheat-insulating lining 100 is in a vacuum state, heat conduction, heatconvection and heat radiation from the exterior to the interior of theheat-insulating lining 100 can be efficiently inhibited. In addition, byvirtue of the porous layer 1 and vacuuming the enclosure body 3, thefootwear article that includes the heat-insulating lining 100 can bemaintained relatively lightweight.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretation andequivalent arrangements.

1. A heat-insulating lining for a footwear article, comprising: anenclosure body made from an air-impermeable thermoplastic material anddefining an inner space; and a porous layer disposed in said inner spacesuch that said enclosure body encloses said porous layer intimately;wherein said inner space in said enclosure body is in a vacuum state. 2.The heat-insulating lining for a footwear article as claimed in claim 1,wherein the air-impermeable thermoplastic material is selected from thegroup consisting of nylon, PE, TPU, PET, PVA, PAN, and combinationsthereof.
 3. The heat-insulating lining for a footwear article as claimedin claim 1, wherein said porous layer is made from a material selectedfrom the group consisting of open-cell type polyurethane, polyesterresin, glass fiber, open-cell type polyethylene, open-cell typeethylene-vinyl acetate copolymer, and combinations thereof.
 4. Theheat-insulating lining for a footwear article as claimed in claim 3,wherein said porous layer further contains molecular sieve and activecarbon.
 5. The heat-insulating lining for a footwear article as claimedin claim 1, wherein said porous layer has a surface with a honeycombstructure.
 6. The heat-insulating lining for a footwear article asclaimed in claim 1, further comprising a reflecting layer that isinterposed between said enclosure body and said porous layer, saidreflecting layer being made from a metal material having lowheat-conductivity.
 7. The heat-insulating lining for a footwear articleas claimed in claim 6, wherein said metal material is aluminum foil. 8.The heat-insulating lining for a footwear article as claimed in claim 1,wherein said enclosure body has an outer surface with upper and lowersides, said heat-insulating lining further comprising a foam layerattached to one of said upper and lower sides of said outer surface ofsaid enclosure body.
 9. The heat-insulating lining for a footweararticle as claimed in claim 8, further comprising a heat-insulatinglayer attached to the other of said upper and lower sides of said outersurface of said enclosure body.
 10. A footwear article, comprising anoutsole; an upper interconnected with said outsole so as to define awearing space therebetween; and a heat-insulating lining disposed insaid wearing space and attached to said outsole, said heat-insulatinglining including an enclosure body made from an air-impermeablethermoplastic material and defining an inner space, and a porous layerdisposed in said inner space such that said enclosure body encloses saidporous layer intimately; wherein said inner space in said enclosure bodyis in a vacuum state.
 11. The footwear article as claimed in claim 10,wherein said outsole is formed with a cavity so as to receive fittinglysaid heat-insulating lining.
 12. The footwear article claimed in claim10, wherein said porous layer further includes molecular sieve andactive carbon.
 13. The footwear article as claimed in claim 10, whereinsaid porous layer has a surface with a honeycomb structure.
 14. Thefootwear article as claimed in claim 10, wherein said heat-insulatinglining further includes a reflecting layer that is interposed betweensaid enclosure body and said porous layer, said reflecting layer beingmade from a metal material having low heat-conductivity.
 15. Thefootwear article as claimed in claim 14, wherein said metal material isaluminum foil.
 16. The footwear article as claimed in claim 10, whereinsaid enclosure body has an outer surface with upper and lower sides,said heat-insulating lining further including a foam layer attached toone of said upper and lower sides of said outer surface of saidenclosure body.
 17. A footwear article, comprising an outsole; an upperinterconnected with said outsole so as to define a wearing spacetherebetween, said upper including a skin layer and an inner liningconfronting said skin layer; and a heat-insulating lining that issandwiched between said skin layer and said inner lining of said upperand that is attached to said outsole, said heat-insulating liningincluding an enclosure body made from an air-impermeable thermoplasticmaterial and defining an inner space, and a porous layer disposed insaid inner space such that said enclosure body encloses said porouslayer intimately; wherein said inner space in said enclosure body is ina vacuum state.
 18. The footwear article as claimed in claim 17, whereinsaid porous layer has a surface with a honeycomb structure.
 19. Thefootwear article as claimed in claim 17, wherein said heat-insulatinglining further includes a reflecting layer that is interposed betweensaid enclosure body and said porous layer, said reflecting layer beingmade from a metal material having low heat-conductivity.
 20. Thefootwear article as claimed in claim 17, wherein said metal material isaluminum foil.